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Test Code LAB757 von Willebrand Factor Antigen, Plasma

Performing Laboratory

Barnes-Jewish Hospital Laboratory

Methodology

Immunoturbidimetric Assay

Literature References:

HemosIL von Willebrand Factor Antigen package insert issued 02/2010, Instrumentation Laboratory.

Specimen Requirements

Specimen Type: Plasma

Container/Tube: Light-blue top (citrate)

Specimen Volume: 1 Full tube

Specimen Minimum Volume: Full tube

Collection Instructions:

  1. Draw a discard blue top tube prior to drawing a light-blue top (citrated) tube if using a Winged Infusion Set.  Discard tube should be under filled and discarded.
  2. Clotted blood or an insufficient specimen is not acceptable.
  3. Avoid phlebotomy techniques which cause hemolysis and heparin contamination.
  4. Follow nursing policy on volume of blood to discard prior to collecting blood from indwelling heparinized catheters.

Analyte Stability:

4 hours at 18° C to 24° C.

Platelet-free plasma can be frozen at -20 for transport on dry ice up to 72 hours
or stored 6 months at -70° C.


Additional Information: If the patient is a hospital patient and the hematocrit is >55%, call Barnes-Jewish Hematology Laboratory at 314-362-5203 for instructions.

Day(s) Test Set Up

Monday, Wednesday, and Friday

Cut-off time: 0700

Turnaround Time:

STAT: not available

Routine: results available the day of testing

Test Classification and CPT Coding

85246

Reference Values

55%-200%

Literature References:

1. Sukhu K, Martin PG, Cross L, Keeling DM, Giangrande PL. Evaluation of the von Willebrand factor antigen assay using an immuno-turbidimetric method automated on the MDA 180 coagulometer. Clin Lab Haematol 2000;22(1):29-32.

2. Sadler JE. A revised classification of von Willebrand disease. Thrombosis and haemostatis. FK Schattauer Verlagsgesellschaft mbH (Stuttgart), 1994;71;520-5.

Specimen Transport Temperature

Ambient Yes/Refrigerate NO/Frozen Yes

 

Additional Information

For BJH Laboratory Use Only

Analyte Stability:

4 hours at 18° C to 24° C.

Platelet-free plasma can be frozen at -20 for transport on dry ice up to 72 hours
or stored 6 months at -70° C.

Laboratory Processing Instructions:
Test performed in BJH Core Lab.

LOINC Code Information

Name                 LOINC Code

vWF Antigen      6012-9